function Snake(ele){
    this.ele=ele

    this.len=20

    // 存蛇
    this.snakeObj = [
        { x: 3, y :2, color:'red', ele:null},  //蛇头
        { x: 2, y :2, color:'blue', ele:null}, // 蛇的身体
        { x: 1, y :2, color:'blue', ele:null}  // 蛇的身体
    ]

    this.direction= 'right'

}

Snake.prototype.remove=function(){

    for(let i=0;i<this.snakeObj.length;i++)
    {
        if(this.snakeObj[i].ele)
        {
            this.ele.removeChild(this.snakeObj[i].ele)
        }
    }
}

Snake.prototype.create=function(){

    this.remove()

    for(let i=0;i<this.snakeObj.length;i++)
    {
        let divObj=document.createElement('div')

        divObj.style.width=this.len+'px'
        divObj.style.height=this.len+'px'
        divObj.style.position='absolute'
        divObj.style.left =  this.snakeObj[i].x*this.len+'px'
        divObj.style.top =  this.snakeObj[i].y *this.len+'px'
        divObj.style.background = this.snakeObj[i].color
        
        this.snakeObj[i].ele = divObj

        this.ele.appendChild(divObj)
        
    }
}

Snake.prototype.move=function(){
    // for(let i=0;i<this.snakeObj.length;i++)
    // {
    //     this.snakeObj[i].x += 1  
    // }
    for (let i = this.snakeObj.length - 1; i>0; i--) {
        // console.log(this.snakeObj[i])
        this.snakeObj[i].x = this.snakeObj[i-1].x
        this.snakeObj[i].y = this.snakeObj[i-1].y
    }

    switch(this.direction){
        case 'top':
            this.snakeObj[0].y -= 1
            break;
        case 'bottom':
            this.snakeObj[0].y += 1
            break;
        case 'left':
            this.snakeObj[0].x -= 1
            break;
        case 'right':
            this.snakeObj[0].x += 1
            break;
    }

    this.create()
}










